// erasureObjects - Implements ER object layer.
type erasureObjects struct {
	setDriveCount      int
	defaultParityCount int

	setIndex  int
	poolIndex int

	// getDisks returns list of storageAPIs.
	getDisks func() []StorageAPI

	// getLockers returns list of remote and local lockers.
	getLockers func() ([]dsync.NetLocker, string)

	// getEndpoints returns list of endpoint belonging this set.

	testShuffleDisks(t, z)
}

// Test shuffleDisks which returns shuffled slice of disks for their actual distribution.
func testShuffleDisks(t *testing.T, z *erasureServerPools) {
	disks := z.serverPools[0].GetDisks(0)()
	distribution := []int{16, 14, 12, 10, 8, 6, 4, 2, 1, 3, 5, 7, 9, 11, 13, 15}
	shuffledDisks := shuffleDisks(disks, distribution)
	// From the "distribution" above you can notice that:

		copy(eps, s.endpoints.Endpoints[setIndex*s.setDriveCount:setIndex*s.setDriveCount+s.setDriveCount])
		return eps
	}
}

// GetDisks returns a closure for a given set, which provides list of disks per set.
func (s *erasureSets) GetDisks(setIndex int) func() []StorageAPI {
	return func() []StorageAPI {
		s.erasureDisksMu.RLock()
		defer s.erasureDisksMu.RUnlock()

	CompleteMultipartUpload(ctx context.Context, bucket, object, uploadID string, uploadedParts []CompletePart, opts ObjectOptions) (objInfo ObjectInfo, err error)

	GetDisks(poolIdx, setIdx int) ([]StorageAPI, error) // return the disks belonging to pool and set.
	SetDriveCounts() []int                              // list of erasure stripe size for each pool in order.

	// Healing operations.

	}
	return nil
}

// Return the disks belonging to the poolIdx, and setIdx.
func (z *erasureServerPools) GetDisks(poolIdx, setIdx int) ([]StorageAPI, error) {
	if poolIdx < len(z.serverPools) && setIdx < len(z.serverPools[poolIdx].sets) {
		return z.serverPools[poolIdx].sets[setIdx].getDisks(), nil
	}
	return nil, fmt.Errorf("Matching pool %s, set %s not found", humanize.Ordinal(poolIdx+1), humanize.Ordinal(setIdx+1))
}

	if err != nil {
		t.Fatal(err)
	}

	erasureDisks := xl.getDisks()
	z.serverPools[0].erasureDisksMu.Lock()
	xl.getDisks = func() []StorageAPI {
		for i := range erasureDisks[:6] {
			erasureDisks[i] = newNaughtyDisk(erasureDisks[i], nil, errFaultyDisk)
		}
		return erasureDisks
	}

	// Simulate read quorum failure by taking enough disks offline
	// With 16 disks (EC 8+8), read quorum is 9. Taking 8 disks offline leaves only 8,
	// which is below read quorum.
	erasureDisks := xl.getDisks()
	z.serverPools[0].erasureDisksMu.Lock()
	xl.getDisks = func() []StorageAPI {
		for i := range erasureDisks[:8] {
			erasureDisks[i] = nil
		}
		return erasureDisks
	}
	z.serverPools[0].erasureDisksMu.Unlock()

		}); err != nil {
			t.Fatal(err)
		}
	}

	setDisks(nil, nil, nil, nil)

	rd := mustGetPutObjReader(t, bytes.NewReader(data), int64(len(data)), "", "")
	_, err = objLayer.PutObject(ctx, bucket, object, rd, ObjectOptions{
		Versioned: true,
	})
	if err != nil {
		t.Fatal(err)
	}

	setDisks(orgDisks[:4]...)
	disk := getDisk(0)

	if err != nil {
		t.Fatalf("Failed to make a bucket %v", err)
	}

	object := "object"
	data := bytes.Repeat([]byte("a"), smallFileThreshold*32)
	z := obj.(*erasureServerPools)

	erasureDisks, err := z.GetDisks(0, 0)
	if err != nil {
		t.Fatal(err)
	}

	for i, test := range testCases {
		t.Run(fmt.Sprintf("case-%d", i), func(t *testing.T) {

package cmd

import (
	"context"
	"math/rand"
	"sync"
	"time"
)

func (er erasureObjects) getOnlineDisks() (newDisks []StorageAPI) {
	disks := er.getDisks()
	var wg sync.WaitGroup
	var mu sync.Mutex
	r := rand.New(rand.NewSource(time.Now().UnixNano()))
	for _, i := range r.Perm(len(disks)) {
		wg.Add(1)
		go func() {
			defer wg.Done()
			if disks[i] == nil {